As John was baptizing those who came confessing their sins, he saw the Pharisees and Sadducees approaching, to which he called to them, saying,
“You brood of vipers! Who warned you to flee from the coming wrath? Produce fruit in keeping with repentance. And do not think you can say to yourselves, ‘We have Abraham as our father.’ I tell you that out of these stones God can raise up children for Abraham.” (Matthew 3)
They didn’t pay heed to this and argued this point to Christ Jesus, Himself (John 8). Jesus makes an interesting distinction, though, between being descended from and children of Abraham, saying, essentially, “though you are descendants of Abraham, you are certainly not his children, for you are looking for a way to kill me, a man who has told you the truth that I heard from God. Abraham did not do such things.” Indeed, he lived by faith and listened to the truth, not opposing it in the least.
Paul elaborates, writing that it is not the physical ancestry which made one a “child of Abraham,” but a spiritual ancestry in which all of the children of the promise are Abraham’s children. The focus of the religious elite, in those days, was founded in the physical ancestry with which they expressed their authority, yet Abraham was credited before the circumcision! The circumcision was a sign of the righteousness by faith – a seal, as it were, thus the promise, by which one may be considered a “child of Abraham” was the spiritual inheritance passed on to the children of many nations who believed in the truth. They had the Law, yet this merely lead to condemnation, for no man has kept the Law perfectly (Rm. 3:9-20; 4). In a way, we can see that God most certainly did make children of Abraham from stones, if you will, for, just like stones, we gentiles were lifeless.
Gloria in Excelsis Deo.